1. Field of the Invention
The present invention relates to a method and system for resuming data processing in a computer.
2. Description of the Related Art
Owing to the advances of semiconductor technologies, microprocessors, peripheral-equipment controlling LSIs and memory LSIs have become available very inexpensively recently. High-performance computer systems can be constructed by a combination of those LSIs. With a personal computer, which is a typical example of the high-performance computer systems, when power is turned on, its component LSIs are initialized and a system boot program is read from a storage device, such as a floppy disk or a hard disk, into a memory so that messages are displayed on a display.
On the other hand, where an automatic execution file is stored, a program set in the file is started so that titles of programs are displayed. Power is turned off after predetermined processing is terminated by the execution of an application program.
When data processing is interrupted (power is turned off) and the data processing is resumed afterward (from the state immediately prior to the interruption), data readout and setting of the screen must be performed again.
A battery-driven personal computer has a function to instantly restore the state immediately prior to the turn-off of power by supplying electric power from a battery to a memory even after power is turned off. However, an AC-driven personal computer has no self-contained battery having enough capacity to always supply the power source to a memory and so on. But the AC-driven personal computer only includes a small capacity battery, which cannot be used to back up data or the state during a long time after the personal computer is turned off. In order to restore the state immediately before the turn-off of power, therefore, the above operations are required.
From the foregoing, AC-driven personal computers are required to have facilities for resuming data processing instantly without the need for a self-contained battery.